Shock absorbing and buoyant vest



Jan. 4, 1944. H. PFLEUMER SHOCK ABSORBING AND BUOYANT VEST Filed May 28,1942 FIG.4.

ATTORNEY Patented Jan. 4, 1944 SHOCK ABSORBING AND BUOYANT VEST HansPfleumer, New Brunswick, N. 1., asslgnor to Rubatex Products, Inc.

poration of Delaware New York, N. 3., a cor- Application May 28, 1942,SerialNo. 444,892

4 Claims.

My invention relates to a. shock absorbing and buoyant vest which hasthe double purpose of protecting the wearer against-the shock which mayoccur in the case of bomb blasts and the like, and is also adapted bythe nature of its construction for use as a life preserving vest.

Since underwater blasts frequently occur in marine disasters, a buoyantlife preserving vest, which is also shock absorbing, may become ofextreme importance.

Where high explosive blasts occur, injury to personnal is not confinedto the immediate area of demolition, but, depending on the nature of theexplosive charge, may occur, through the socalled blast effect, over anarea having a radius of as much as a quarter of a mile. This blasteffect arises from a compression wave immediately followed by a suctionwave radiating from the center of the explosion. These two successivewaves set up mechanical stresses about any object encountered within theradius of the blast effect, and cause their destruction.

When a person is subjected to these waves within the radius of the blasteffect, the successive intense compression followed immediately byviolent suction causes severe physical injury. These injuries occur forthe most part in the thoracic portion of the body above the diaphragm.The diaphragm itself, and the abdominal walls and the viscera containedtherein are usually sufflciently resilient to survive this seriesof-successive mechanical shocks. The thorax however, above thediaphragm, is relatively rigid and contains the most vital and delicateorgans. The blast effect, owing to the rigidity of the thorax, mayactually have sufilcient 'force to break the ribs, and most often hassuflicient mechanical force upon the muscles of the chest to collapsethe lungs as Well as to injure the heart.

The collapse of the lung occurs both because of the compression wavesand the suction waves. The compression wave tends to collapse the thoraxand press the chest walls in upon the lungs, so that the air is expelledtherefrom. This com pression wave is immediately followed by the suctionwave which draws out any air which may remain.- The victim isimmediately rendered unconscious and asphyxi'ated, and may suffer otherphysical injuries as above pointed out.

The most important force which causes physical damage, and the forcewhich may most readily be counteracted is. the compression wave, sinceit causes a physical injury aswell as collapses the lungs.

Should a person survive the effect or the comgas expanded rubber,

pression wave, he may most likely be suflicieiitly conscious at the endof the suction wave to: be able to regain his breath. A combination ofthe two, however, is highly dangerous.

My shock absorbing vest is of anature peculiarly appropriate forabsorption of the shock of this compression wave. Essentially, itcomprises a vest made of soft closed cell gas expanded rubber whichclosely surrounds the thorax.

Closed cell gas expanded rubber is distinguishable from sponge rubber inthat it consists of a multiplicity of minute closed cells th majority ofwhich do not communicate with adjacent cells, each of the minute cellshaving a small gas bubble enclosed therein. Each of the minute gasbubbles may, in fact, consist of a gas under pressure, thus increasingthe shock absorbing effect. In the case of sponge rubber, instead of amultiplicity of minute sealed or closed cells, a multiplicity ofcommunicating channels are formed so that a sponge rubber sheet or vestwould be porous and thus permit the compression wave in blast effect tomake itself felt.

In the case of soft closed cell gas expanded rubber, when it is used asa shock absorbing vest of this kind, the compression wave impinges onthe outside of the vest and the force thereof is transmitted to theminute gas filled cells adjacent the outer surface of the vest.

These cells are compressed, and transmit the shock to thenext inwardlyadjacent closed cells through the elastic cell walls of the closed cellThe forceof the shock thus transmitted through the first layer of cellshas been diminished by the force necessary to compress the gas bubbleswithin the cells themselves. The shock is transmitted again and againthrough successive layers of the vest until it reaches the interiorlining thereof, and the body of the wearer; but in each case, the shockmust successively be transmitted through gas bubble after gas bubble sothat in each case, the force of the shock is partially absorbed bycompression of the successive gas bubbles. I In addition to this form ofabsorption, the successive gas bubbles, it must be noted, are compressednot merely inwardly, but also laterally by the force which is impingedon only one side thereof, so that the shock is transmitted not only.

inwardly, but also laterally through the sheet forming the vest itself,and thus'around the body of the wearer instead of directly toward thebody of the wearer. v

Obviously, this transmission of the shock ,tion and drawing in which:

through the vest, and the absorption of the force thereof, fromgas-bubble to gas bubble, occupies the merest fraction of a second.Nevertheless, the shock is appreciably diminished owing to the fact thatthe successive gas bubbles must be compressed before the force of thecompression wave is transmitted onward, and this compression is notmerely in an inward direction, but in all directions. ""1

Since the soft closed cell gas expanded rubber sheet or vest has amultiplicity of extremely minute cells, the transmission of the shockfrom cell to cell will appreciably diminish the force thereof, as wellas distribute the force so as to make the shock bearable when it finallyreaches the person of wearer.

For optimum results, the sheet forming the vest should be at leastone-half inch thick, although I preferthat it be as much asthreequarters of an inch or one inch thick.

Since the minute closed cells formed in the gas expanded closedcell'rubber areof the order of 3 21170 /100 of an inch in diameter, itwill be clear that the multiplicity of minute cells thus formed will actas an appropriate shock absorber for the compression waves.

This shock absorbing quality holds true whether the blast efiect occursin air or in water. The compression wave is transmitted in a similarmanner through water or through air. But when the wave reaches thewearer of the vest, whether he is immersed in water or in air, the sameabsorptiv effect will take place. Where the vest is to be utilized as acombintion buoyant vest and shock absorbing vest for use as a lifepreserver in water, then I have found that the optimum thickness thereofshould be from three-quarters of an inch to one inch in order to provideappropriately for buoyancy of the body of the wearer. It is obviouslypeculiarly adapted to suchlife preserving-purposes since themultiplicity of minute gas filled cells are'individually sealed not onlyfrom each other but with respect to any outside fluid. The material ofthe vest is therefore impervious to water, and thus acts as an efficientbuoyancy producing member. As

a matter of fact, in the case of soft closed cell gas expanded rubber,the specific gravity of the material may be as low as .1 or less, sothat an appropriate buoyant effect may be obtained with a minimum ofmaterial. I,

' The primary object of my invention therefore, is the provision of alife preserving vest which is adapted to absorb'the'shock of anexplosive blast. e

As a corollary object of my invention, my life preserving vest is alsowater impervious and is sufiiciently buoyant to support the wearerthereof in water.

Another object of my invention is to form a life preserving, shockabsorbing, and buoyant vest from closed cell gas expanded rubber.

Still another object of my invention is the provision ofsimple'fastening means in connection with the life preserving vest aboveset forth which will permit the user thereof quickly to secure the sameto his body.

\ Still anotherobject of my invention is the provision of a simplifiedslide fastener element vulcanized into the material of my lifepreserving vest.

These and'm'any other objects of my invention will become apparent inthe following descrip- Figure 4 is a view showing the manner in which myshock absorbing buoyant vest may be secured to the body of the user.

Referring now to Figures 1 and 2, I have here shown a shock absorbingbuoyant vest I0 consisting of a body embracing member I I, and slidefastener element l2 and I3 at opposite edges thereof. One edge of thevest III may be notched at H and IS in order to make the vest fitproperly under the arms of the wearer.

The material I I of the body portion of the vest I0 is formed of softclosed cell gas expanded rubber. Gas expanded rubber of this type hasbeen described and the manner of manufacture thereof has been set forthin Denton Reissue Patent No. 21,245, as well as in Patent Nos.2,086,513,

external gas pressure which will cause impregnation of the gas, forinstance nitrogen, thereinto; the expansion of the rubber within aconfining mold, while at the same time partially curing or vulcanizingthe same so that the inert gas impregnated therein may expand while therubber cell walls may be given suflicient strength by the vulcanizationto permit expansion, while at the same time preventing the bursting ofthe minute cells thus formed; When expansion has occurred, theexpandedrubber is then subjected to a final vulcanizing process which"sets the rubber in its fully expanded form with the minute cells sealedfrom each other, and containing gas therein.

, gas expandedclosed cell form.

In either -caseyby controlling the expansion and controllingthe amountof sulphur included in the rubber mix, the softness of the rubber andthe minuteness of the cells may be predetermined in accordance with thepatent above mentioned.

The processes may follow the patents abov mentioned or the processes maybe the same as those described in connection with the application SerialNo. 159,706, now Patent No. 2,299,593, dated October 20, 1942, assignedto the assignee of the present invention; or if it is desired tomaintain the gas within the closed cells at-an elevated pressure, thenthe processes may be that set forth in my application Serial No.407,729.

The slide fastener may consist ofelements l2 and i3 adapted to mesh witheach other in a manner which is well known in the art; and which aresecured at opposite edges of the vest "I. As is seen in Figures 2 and 3,the slide fastener element consists of inter-engaging members 20 securedto a tape 22. The tape 22 is preferably approximately three-quarters ofan inch 7 in width, and is provided with a plurality of perforations 25which are preferably of the order of three-eightsof an inch in diameter,and-approximately three-quarters of an inch apart.

After the material ll forming the sheet or body of the vest I0 has beenprecured and before If desired, it may be possible to form the vestoutof at least two plys of sheet material, which,

after the precure, are laid together and then during the final curingstage vulcanized together. In such case, when the two sheets are laidtogether, the tape 22 of the slide fastener l2 may be inserted betweenthe edges of the sheets to be vulcanized therein in the mannerpreviously described.

By reason of the fact, that, during the final vulcanizlng or curingstage, the rubber material flows through the perforations 25 in the tape22 of the slide fasteners I 2 and Hi, the tapes are securely integratedwith the body of the vest and the slide fastener elements l2 and I3 aresecured thereto.

The slide fastening means or any other fastening means which may beusecfis, of course, sufiiciently narrow so as not to provide asuflicient area over which a compression wave may be felt. In addition,the securement of the fastening means in the edge of the resilient vestprovides for shock absorption at that area.

However, the fastening means may be covered by a flap of closed cellcellular rubber material;

or the fastening may be so arranged that the edges of the vest abutfiush against each other.

Where a flap is used, it may be secured over one I ment of a pair offlaps encasing the fastening.

means when it is closed is, of course, not necessarily limited to a vestwhich is made of plied material.

In Figure 4, I have shown the manner in which the vest III of myinvention may be placed about the body of-the wearer so that it protectsthe thoracic area of the person wearing it.

Preferably, when the vest is worn, it makes a good contact, fittingsnugly around the body to prevent air or water from entering between thevest and body to provide a path for the compression wave. While it isthus desirable to have several sizes available, nevertheless, owing tothe stretchable characteristics of my vest, it may fit rather tightlywithout substantial inconvenience. Further, since my vest encases thebody tightly and fits under the arms, it is not subject to the objection(common in other life preservers) that it may be forced up violentlyagainst the chin and neck of the wearer when he strikes the water.

Since the buoyant quality of my vest is derived from a multiplicity ofminute sealed cells, it is not subject to the objection, found ininflatable rubber members, that punctures or tears will interfere withits buoyancy.

My vest, when stored, is also not nearly as great a fire hazard as otherlife preserving media as for instance kapok. The rubber is not asinflammable; and the gas (which is preferably nitrogen) stored up in themultiplicity of cells does not support combustion.

My life preserving vest, as previously pointed out, is shock absorbingas well as buoyant. It is made of standard sheet material which in turnis formed of a standard and now well known product, and hence is simpleto manufacture.

The multiplicity of minute sealed cells within the body of the material,acts to absorb the efiect of the compression wave in the case ofexplosive blasts and also acts to preserve the buoyancy of the vest andhence of the person wearing it. Since the vest of my invention is madeof ordinary sheet material, it may be stowed fiat in order to savespace, or it may be rolled up. When worn, it will not chafe the body,and it will permit free arm movement. Owing to its formation and themanner in which it is to be used, it is positive in fastening, andcannot come off; and furthermore, the vest is so arranged as to .beW013i in such manner that its buoyancy is fully use Many variations andmodifications of my invention should now be obvious to those skilled inthe art. I prefer therefore, to be bound not by the specific disclosuresherein, but only by the appended claims.

I claim:

1. A shock absorbing buoyant vest adapted to be worn on and completelysurround the thoracic portion of the body, said vest consisting entirelyof a flat sheet of soft cell-tight cellular rubber material and havingnotches along one edge shaped to fit snugly under the armpits of thewearer,

and slide fastening means secured to opposite edges of said flat sheetand adapted to interengage to connect said edges together. when saidvest is to be worn, said slide fastening means each comprising elementsmounted upon a tape, each tape being secured in an edge of the vest.

2. A shock absorbing buoyant vest adapted to be worn on and completelysurround the thoracic portion of the body, said vest consisting entirelyof a flat sheet of soft cell-tight cellular rubber material and havingnotches along one edge shaped to fit snugly under the armpits of thewearer, and slide fastening means secured to opposite edges of said flatsheet and adapted to interengage to connect said edges together whensaid vest is to be worn, said slide fastening means each comprisingelements mounted upon a tape, each of said tapes on opposite sides beingsecured in a slit in the edge of the vest, the rubber material of thevest being vulcanized to hold said tapes in place.

3.'A shock absorbing buoyant vest adapted to be worn on and completelysurround the thoracic portion of the body, said vest consisting entirelyof a fiat sheet of soft cell-tight cellular rubber material and havingnotches along one edge shaped to fit snugly under the armpits of thewearer, and slide fastening means secured to opposite edges of said fiatsheet and adapted to interengage to connect said edges together whensaid vest is to be worn, said slide fastening means each comprisingelements mountedupon a tape, each of said tapes-on opposite sides beingsecured in a slit in the edge of the vest, the rubber material of thevest being then vulcanized to hold said tape in place; a. plurality ofopenings in each tape, said rubber material on vulcanization flowingthrough-said openings and anchoring said tapes in place.

4. A buoyant shock absorbing vest of soft cell- HANS PFLEUMER.

